Hi,
You asked:Is it not an unreasonable method to fiddle with stock prices afterwards?
My response is:Yes it is ureasonable. If you were to buy the stock at the end of the day, the price you would pay would be the closing price, not the price adjusted for dividends by Yahoo.
if you are going to check data of any kind IMO you should check numbers tat all are the same. With Yahoo, it is possible with monthly dividend payers to have 5% of you numbers adjusted. That IMO is too much "adjusting" to what actually happened.
Bernie